Did You Know? Some people report a fishy smell after supplementing with L carnitine. This happens because certain gut bacteria convert carnitine to trimethylamine, a malodorous compound found in rotting fish. Revisiting the Role of Carnitine in Heart Disease Through the Lens of the Gut Microbiota Revisiting the Role of Carnitine in Heart Disease Through the Lens of the Gut Microbiota Does L carnitine cause erectile dysfunction? L Carnitine Erectile Dysfunction: What the Evidence Actually Shows CUD Deficiency Primary Carnitine Deficiency